Means for minimizing inductive disturbances



Get. 2 8, I924. 1,513,224 A. w. COPLEY MEANS FOR MINIMIZING INDUCTIVE DISTURBANCES Filed Au 9, 1916 2 Sheets- Sheet. 1

4 3' mnmi 14 9 /2 WITNESSES: mvENT'o'R Wino/7 [o p/ey Oct; 28, 1924,. 1,513,224 A. W. COPLEY MEANS FOR MINIMIZING INDUCTIVE DISTURBANCES Filed Aug. 9, 1916 2 Sheets-Sheet 2 3:; I A l A I 37 35- '38 WITNESSES INVENTOR 2 63/01 Z M. A/man i d! [op/2y JmMW Patented Oct. 28, 1924.

UNITED STATES PATENT 1,513,224 OFFICE,

ALMON W. COIPLEY, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC 85 MANUFACTURING COMPANY, .A CORPORATION OF PENNSYLVANIA.

MEANS FOR MINIMIZING INDUCTIVE DISTURBANCES.

Application filed August 9, 1916- Serial No. 113,961.

To all whom it may concern.

Be it known that I, ALMoN W. Corner, a citizen of the United States, and a resident of iVillrinsburg, in the county of Allegheny and State of Pennsylvania, have inventeda new and usefullmprovement in Means for.

' of intelligence-transmission circuits, such as telephone and telegraph circuits that, for longer or shorter distances, are located in inductive relation to power circuits which utilize alternating currents.

The object of my invention is to provide practical and efiicient means of the character above indicated.

When a telephone or telegraph circuit is located in proximit to an alternating-urn rent distributing system, such as a railway system, electromotive forces are induced in the intelligencetransmission circuit that may seriously interfere with its satisfactory operation. In an alternating-current railway system, as the train or propelling vehicle moves from one position to another, a primary circuit, comprising a single turn of varying length, is formed. The electromagnetic field produced by the current flow in this primary turn induces alternating electromotive forces in the adjacent telephone or telegraph circuit. The induced electromotive force depends upon the dis tance between the intelligence-transmission circuitand the railway or power-transmission circuit, the current-flow in the latter, the variations of the currents obtaining in the power circuit, the lengths of the circuits, and, in the case of a railway circuit, whether the current returns wholly through the track rails or partially through the earth at a greater or less distance from the rails.

According to the present invention, I pro pose to minimize or neutralize the electrometive forces induced in intelligence-transmis sion and similar circuits by opposing them with equal and oppositely-directed electromotive forces that are generated by circulatin currents 1n the railway s stem. the b v A purpose of which s to nsure satlsfzlctory operation of the adjacent intelligence-transmission circuits. 7

My invention will be more fully explained in connection with the following description and the accompanying drawing, in which Fig. 1 is a. diagrammatic representation of a simple system arranged in accordance with my invention; and Fig. 2 is a diagram of a modified form of the system shown in Fig. 1.

Referring to Fig. 1, an electric railway system, which is representative of a suitable power-transmission system, comprises a trolley conductor 1 and a track 2 that are supplied with alternating currents for propulsion purposes from high-tension feeder mains 8. The supply mains 3 are interconnected, at intervals, to the trolley conductor through a plurality of spaced transformers 4 and 5 which are employed usual ly to reduce the transmission voltage of the feeders to the operating voltage of the railway system. The feeders 3 are connected to any suitable source of power supply (not shown). In proximity to the railway system is an intelligence-transmission circuit 6 represented as a telegraph circuit. The circuit 6 parallels the railway system for a greater or less distance and, therefore, is subject to inductive eflects arising from the flow of power currents in the railway system. A second conductor 7, so disposed with respect to the telegraph conductor 6 that it will be subjected to similar or the same inductive influences as are impressed upon the telegraph conductor, parallels the railway system for a greater or less distance and is utilized to furnish the electromotive forces induced in it to indirectly compensate for the disturbing electromotive forces induced in the intelligence-transmission conductor 6.

The power transformer 4 is provided with a secondary winding 8 having a number of taps 9 which are so positioned as to be en gaged by the rotatable arm 10 of a power relay 11. The secondary winding 12 of the power transformer 5 is not necessarily provided with taps for adjusting purposes. Under normal operating conditions, the voltage impressed upon the railway system by means of the transformer 4 is equal to the voltage impressed upon the railway system by means of the transformer 5, and, consequently, no circulating currents, other than power'currentsyare flowing in the railway system. 7 V

- The power relay 11, which may be of any usual type adapted for this service, co i-- prises a stationary coil 13, one terminal of which is connected to the trolley conductor 1 and the other terminal of which is con- 7 nected, by means of a lead 14, to the rota- 7 table arm 10. The power currents, therefore, supplied to the trolley conductor 1, must-- flow through the'current coil 13 of the power relay 11.

coil 15 of the power relay 11. To the coil 15 is attached the rotatable arm'10, both beinginounted' to rotate about apivot 16 and thecoil 15 being supplied with. current through a secondary winding 17 of a trans former 18, the-primary winding 19 thereof being connected in series-circuit relationship with the auxiliary or protective conductor 7. Since the primary. winding 19 of the transformer 18 isin the circuit of the protective conductor 7 and, consequentthe induced currents flowing inthe protective conductor 7.

As above mentioned,under normal conditions, the voltages impressed upon the trolley conductor by means of the trans. formers 4 and 5 will be such that no neu tralizing currents will flow in the trolley conductor. But, when the induced currents in the" -intelligencetransmission conductor and, therefore, in the protective conducre i 1 tor 4, reach values that are likely to interfere with satisfactory operation, the power relay 11 will selectively engage aparticular tap 9 upon the transformer 4 in order to establish a circulating current in the trolley conductor 1 that will induce neutralizing electromotive forces in the ihtelligence transmission conductor 6. and in the pro tective conductor 7. Thecirculating current will vary, depending upon the current flow in the current coil- 13 and the current flow in the movable coil 15 of the power re lay 11, the'latter current flow being proportional to the disturbing electromotive forces obtaining in the conductors 6 and 7. Itwill be noted that the power relay 11 is so designed as to be selectively operative for different directions of the alternatingcurrent voltages appearing in the conductor 6. As a result, the circulating currents obtaining in the trolley conductor 1 are made In the inductive" field of" the stationary-coil 13 is disposed a second to flow in the one or the other direction, depending upon whether the load is in; proximity to the power transformer 4 or to the power transformer 5. Again, the neutralizing currents flowing in the trolley conductor 1 will be of such value as to substanlv preclude the flow ofunbalanced disoing currents in the conductor 6.

In Fig. 2 I have shown my inventionemployed in connection with a railway system having the trolley conductor and the tracl: rails inductively interlinked by means of booster transformers 35. The trolley conductor. 1 is provides, at spaced intervals, with insulating joints 36 across which primary windings 37 'of the. booster trans The purpose and function of the booster transformers 35arefully. described in a U. S. Patent No. 1,196,300, issued to Charles F. Scott, and assigned to the Westinghouse Electric and Manufacturing Company.

In this system, as hereinbefore described, the high-tension feeder conductors 3- are connected to the trolley conductor '1 by means of spaced transformers 4 and 5, the

fornierbeing provided with a plurality of taps. 9 that may be engaged by a rotatable arm 41 which, in turn, is connected, by means of a conductor 42 and a current transformer 43:, to the trolley conductor 1. The transformer 5 is shown as being directly connected to the trolley conductor 1, but it will be understood that the transformer 5 may also be provided with a plurality of taps and associated apparatus, as shown in connection with the transformer 4. The conductor 6 is so disposed as to .be influenced by the inductive disturbances arising in the railway system, andthe protective conductor 7 is similarly so placed as to be subject also to the inductive disturbances obtaining in the railway system. In the protective conductor7, a series transformer .44 is inserted, thesecondary. winding 45 of which,

in conjunction with the secondary winding 46 of the transformer 43, serves to influence a power relay device. 47. The power device 47 comprises a stationary coil 48 that isconnected in closed circuit with the secondary winding45and, therefore, generates an inductive action that corresponds to the electromotive forces induced in the protective conductor 7. A rotatable coil 49, to which acontact-n1akihg arm 50 is secured, is connected in closed circuit with the secondary winding 46' and, therefore,

generates an inductive action that corresponds to the current supplied to the trolley conductor 1 by the transformer s. The. power dei'i e may, when not in its normal position, effect engagement with either the one or the other of adjustable contact members 51 and @n eflecting engagement between the arm and either of the contact members 51 and 52, circuit is established for driving a motor 53 that, in turn, operates a worm and wheel mechanism '54 to rotate the arm n The motor 53 is furnished with power from mains 55 between which a reversing switch 56 is inserted. The reversing switch 56 comprises solenoids 5'? and 58 that are selectively energized by the power device 457. The rotatable arm 50 is connected to one of the supply mains 55, and the common terminal of the solenoids 57 and 58 is connected to the other supply conductor 55. Movement of the arm 50 in the one or the other direction closes the appropriate circuitto operate the reversing switch 56. The position of t 1e switch 56 detern'iines the direction of rotation of the motor 53 and, therefore, the particular tap 9 upon the transformer that is selected to neutralize the disturbances impressed upon the conductor 7. As mentioned above, the amount of circulating current obtaining in the railway system is thus regulated in accordance with the electromotive forces induced in the conductor 6 and the current supplied to the railway system through the power transformer 4.

While I have shown and described-several embodiments of my invention, it will be understood that many modifications may be made therein without departing from the spirit and scope of the appended claims.

I claim as my invention:

1. The combination with a conductor of an independent electrical circuit, of an electrical-power-distributing system in inductive proximity thereto, and means influenced by electromotive forces induced in said first conductor for establishing compensating currents in said power system, whereby the inductive eilects arising from the flow of power currents therein are substantially neutralized.

2. The combination with an electrical conductor, of an electrical power system positioned in inductive relation thereto and means influenced by the electromotive forces induced in said first conductor and by the load currents flowing in said power system for neutralizing the electromotivc forces induced in said first conductor by reason of the load currents in the power system.

3. The combination with a conductor of an independent electrical circuit, of an electricalpower-distributing system in inductive relation thereto which comprises a plurality of conductors that are connected to one antler througi soaced transformers, said -'r=.nsformers being provided w h variable Laps and means o vying the taps on said controlle nduced in so. r tor b the cartern.

transformers being provided with varia do taps, and means for varying the taps on said ransfor r said means being controlled by the 'oint action of electromotive forces induced in said independent electrical conductor and the currents flowing in the electrical-p0wer-distributing system.

The combination with a conductor of in independent electrical circuit, of an elecrical-power-distributing system in inducive relation thereto which comprises a plurality of conductors that are connected to one another through spaced transformers, having variable taps, and means for selec- L is tiveiy varying the taps on said transformers in order that proper circulating currents 1 be established in the distributing system which will neutralize the disturbing electromotive forces induced in the indeper dentelectrical conductor.

The combination with a conductor of an independent electrical circuit, of an elec trical-power-distributing system in induci. relation thereto which comprises a plurahty of conductors that are connected to one another through spaced transformers provided with taps, and means for selectively varying the taps upon one of said transformers in order that properly directed circulating currents may be established in the distributing system to neutralize the electromotive forces induced in the independcnt-electrical conductor by the load currents obtaining in the distributing system.

7. The combination with a conductor of an independent electrical circuit, of an electrical-power-distributing system in inductive relation thereto which comprises a plurality of conductors that are connected to one another through spaced transformers having variable taps, and power relay de vices for selectively varying the taps upon one of said transformers in order that currents may be caused to circulate in the' power system which will neutralize the inductive effects impressed upon said independent electrical conductor by reason of the load currents flowing in the power systern.

The combination with a transmission circuit, of a grounded local circuit, a conductor insulated from ground, means for lOO connecting said conductor at two different points to said transmission circuit, one of saidmeans including a variable transformer, an independent circuit inductively related to said local circuit, and a power relay 7 independent circuit inductively related to said conductor, and an lndicating relay device having a coil energized in accordance with the current in said independent circuit and a coil energized in accordance with the current in one of said connecting. means, said device being adjusted to indicate changes required in said auxiliary means in order to minimize inductive interference resulting from currents flowing. in said conductor.

10. In a non-inductive interference systom, the combination with a pair of power stations, of a power circuit tending to cause inductive interference, means connecting said power circuit at spaced points for interchange of power withtherespective power stations, auxiliary means for varying the relative magnitude and direction of the power interchanged between said circuit and the respective power stations, and indicating means for producing an electromotive force proportional to the interfering fields which it'is desired to eliminate;

11. In a non-inductive interference system, the combination with a pair of power stations, of a power circuit tending to cause inductive interference means connecting said power circuit at spaced points for interchange of power with the respective power stations, auxiliary means for varying the relative magnitude and direction of the power interchanged between said circuit and the respective power stations, means for producing an electromotive force proportionalto the interfering'fields which it is de-v sued to eliminate, and an'lndlcatlng relay device having one coil energized in accordance with said electromotive force and acooperating coil energized in accordance with the current flowing in one of said connecting means.

"12. In a non-inductive interference system, the combination with an alternatingcurrent power circuit, one portion of which tends to set up objectionable static fields in the surrounding ether, of an independent electrical conductor in inductiverelationship with the fields set up by the currents in said .ALMON corner 

